package com.atguigu.distributed.lock.leecode.tree;

public class TrieTree {

}
class Trie2{
    private Trie2[] children;
    private boolean isEnd;
    public Trie2(){
        children = new Trie2[26];
        isEnd = false;
    }
    public void insert(String word){
        Trie2 node = this;
        for (int i = 0; i < word.length(); i++) {
            char ch = word.charAt(i);
            int index = ch-'a';
            if(node.children[index]==null){
                node.children[index] = new Trie2();
            }
            node = node.children[index];
        }
        node.isEnd = true;
    }
    public boolean search(String word){
        Trie2 node = searchPrefix(word);
        return node!=null&&node.isEnd;
    }
    public boolean startsWith(String prefix){
        return searchPrefix(prefix)!=null;
    }
    public Trie2 searchPrefix(String prefix){
        Trie2 node = this;
        for (int i = 0; i < prefix.length(); i++) {
            char ch = prefix.charAt(i);
            int index = ch - 'a';
            if(node.children[index]==null){
                return null;
            }
            node = node.children[index];
        }
        return node;
    }
}
class Trie{
    private Trie[] children;
    private boolean isEnd;

    public Trie() {
        children = new Trie[26];
        isEnd = false;
    }

    public void insert(String word) {
        Trie node = this;
        for (int i = 0; i < word.length(); i++) {
            char ch = word.charAt(i);
            int index = ch - 'a';
            if (node.children[index] == null) {
                node.children[index] = new Trie();
            }
            node = node.children[index];
        }
        node.isEnd = true;
    }

    public boolean search(String word) {
        Trie node = searchPrefix(word);
        return node != null && node.isEnd;
    }

    public boolean startsWith(String prefix) {
        return searchPrefix(prefix) != null;
    }

    private Trie searchPrefix(String prefix) {
        Trie node = this;
        for (int i = 0; i < prefix.length(); i++) {
            char ch = prefix.charAt(i);
            int index = ch - 'a';
            if (node.children[index] == null) {
                return null;
            }
            node = node.children[index];
        }
        return node;
    }
}
